Reinforcing clip machine



Sept. 22, 1942. w, H SMITH 2,296,483

REINFORCING CLIP MACHINE Filed July 9, 1940 2 Sheets-Sheet 1 Sept. 22, 1942. w. H. SMITH REINFORCING CLIP MACHINE Filed July Q, 1940 2 Sheets-Sheet 2 Patented Sept. 22, 1942 UNITED STATES TENT OFFICE In Great Britain July 17, 1939 Claims.

In the manufacture of reinforced concrete constructions, such as beams or slabs, it is desirable that the reinforcing members shall be located in correct relation.

This invention provides a machine for the production for this purpose of clips which are pushed on to reinforcing bars when these are placed in the moulds and which separate and locate the bars in correct relative position. Such clips may for example comprise a central portion of substantially U-shape with the limbs thereof bent reversely to provide tail portions.

A machine in accordance with the invention comprises means for feeding a strip of resilient material between relatively movable dies cooperating to bend the strip into the required form and means for separating from the strip a length sufiicient to form the clip.

One of the dies conforms in section to the required shape of the clip and the other die comprises prongs arranged to force the strip into conformity therewith. The U-bends of the clip preferably have a slightly constricted portion past which the reinforcing bars are forced and the prongs on one of the dies of the machine are pivoted so that this constricted portion may be formed by forcing the strip into undercut portions of the other die.

Various objects and advantages of the invention will be apparent from the description of some specific forms which will be described with reference to the accompanying drawings and of which the novel features will be pointed out in the claims.

In the drawings:

Fig. l is a front view of the machine,

Fig. 2 is a side view,

Fig. 3 is a view to an enlarged scale of the dies.

This machine comprises a frame I supporting a fixed bottom die 2 formed with a recess which is of cross-section corresponding to that of the clip. The sides 3 of this recess slope inwardly and a portion 4 of the die projects upwardly from the centre of the recess. This projection is curved on its top surface and is undercut at the bottom so as to form with the sloping sides arcs of a circle 5 corresponding to the bends of the clip between the tail portions and the central U-shaped portion into which the reinforcing bar enters.

Fixed to the frame I above the bottom die 2 are guides 6 in which is movable vertically a head I supporting a top die 8. This top die comprises two prongs 9 pivoted at their ends ID to the head 1 and sloping towards one another. These pron-gs 9 are formed with arcuate grooves H on their inner faces and towards their ends, these groves ll being adapted to bend the strip around the central projection 4 of the bottom die 2 in a smooth curve.

Between the two prongs 9 and projecting from the head 1 is a member l2 concave at its lower end which cooperates with the top of the projection 4 on the bottom die 2 to bend the strip smoothly around this projection.

The head I also carries a shearing blade I3 cooperating with a fixed blade I4 to shear a sufiicient length of material from a strip to form a clip. The strip is fed between the dies 2, 8 and as the head 1 moves downwardly, the shearing blades [3, l4 come first into operation to cut the material and then the upper die 8 forces the material into the lower die 2 to form the clip. An adjustable stop I5 is provided against which the end of the strip abuts to determine the length of material to be cut off.

The strip is fed to the machine, from a coil l6 in a suitably mounted pan or the equivalent, between rollers ll, 18 one of which (H) is arranged to be driven through gearing when the material is to be fed and to be free during cutting and bending operations on the cut-off strip. The other roller I8 is kept in contact with the strip material by pressure of a spring 19 or other equivalent device.

' In the preferred form, the driven roller I1 is coaxial with a pinion 20, the teeth of which engage with the teeth of a larger gear-wheel 2|. Fixed to and coaxial with this large gear-wheel 2| is a ratchet wheel 22 which is rotated by a pawl 23 connected at its other end to one end of a lever 24. This lever 24 is pivoted at 25 to the frame I of the machine and its other end 26 is arranged to project into the path of the head 1. During the latter part of the upward movement of the head, the head contacts with and moves this end 26 of the lever upwards thereby causing the pawl 23 to rotate the ratchet wheel 22 and the large gear 2|. The roller I1 is thus rotated sufficiently to feed the desired length of strip to the dies 2 and 8. During the downward movement of the head the lever 24 falls back to its previous position, the pawl23 riding over the teeth of the ratchet wheel 22.

The pawl 23 is maintained in contact with the teeth of the ratchet wheel 22 by a spring 21 between it and the lever 24 to which it is pivoted.

To vary the feed of the rollers l1, l8 the abutment between the head I and the lever 24 may as shown comprise a screw 28 which may be adjusted to adjust the point in the stroke of the head at which the lever is moved.

The head 1 is moved up and down by means of a bent lever 30 which is pivoted at 3| to the machine frame. One end of this lever 30 engages in a slot 32 in the head and the other arm is moved from the position shown in full lines in Fig. 2 to the position shown in dotted lines to lower the head and vice versa to raise the head. The lever 30 may be moved by means of a treadle 36 or by means of a motor 33 through a crank 34 and connecting rod 35.

In operation, when the movable head 1 begins its downward stroke, the strip material will have been fed against the stop l5 and will be lying across the recess in the bottom die 2. head I descends, the shearing blade l3 cuts off a suflicient length of the strip and the prongs 9 of the top die 8 then contact the strip and force it into the recess. The prongs 9 being pivoted move apart sufiicient to wrap the material around the central projection 4 and are then moved inwardly by the sloping sides 3 of the recess to force the material into the undercut grooves at the bottom of this projection. The ends of the strip are free so that they can slide over the bottom die 2 to allow the bending to take place.

The movable head then moves upwardly and the finished clip can be removed by an ejector suitably connected with the ram of the machine and arranged to operate during the upward motion of the ram. Towards the end of its upward stroke, the head moves the lever and through the pawl and ratchet wheel moves the feed rollers to feed the strip into position ready for another clip to be cut off and formed.

The ejector mechanism comprises prongs 3'! which are moved forward to engage the spring clip after it has been formed and at the moment when the head of the press is rising. These prongs 3'! may be operated by the lower extremity of the operating pedal lever 30 (or an equivalent part) when this is returned at the end of the downward stroke of the head and may be returned by means of springs (not shown). Adjustment can be provided between the prongs and the pedal lever.

It will be understood that the invention is not restricted to the details of the specific form described. For example, the feed mechanism for the strip might be driven from some part of the machine other than the head and through cranks, cams or other equivalent devices.

I claim:

1. A machine for the production of clips for positioning reinforcement in concrete construction comprising a stationary frame, a die carried by the frame, a head reciprocable in guides in the frame above the die, a second die carried by the head cooperating with the first die to form the clip, one of the dies having a central projecting As the portion with undercut recesses and the other die having pivoted prongs movable towards one another to close strip material around the central projecting portion of the other die and into the undercut recesses thereof, a fixed shearing blade carried by the frame, a shearing blade carried by the movable head and cooperating with the fixed blade to shear a length from strip material prior to the operation of the dies thereon, a pair of feed rollers, ratchet mechanism in driving connection with one of the feed rollers, a lever pivoted to the frame and in driving connection with the ratchet mechanism, one end of this lever lying in the path of 'the reciprocable head and being moved thereby during the upward stroke thereof to drive the feed roller to feed strip material between the shearing blades and the dies in succession and means to reciprocate the head in the guides.

2. A machine as defined in claim 1 having an abutment between the reciprocable head and the ratchet-operating lever adjustable to vary the point in the stroke of the head at which the lever is moved.

3. A machine for the production of clips for positioning reinforcement in concrete construction, comprising a frame, a fixed die carried by the frame and having a central rounded projection and spaced straight side walls downwardly convergent, a support carried by the frame, a slide guided by and movable in the support, a

movable die carried by the slide and including.

pivoted arms to enter the fixed die, the straight side walls of the fixed die compelling the pivoted arms to force the material into exact conforming contact with the central rounded projection of the fixed die, means for feeding the material to a position on the rounded projection of the fixed die, and adjustable means actuated by and in the upward movement of the slide to compel a predetermined selected operation of the feeding means.

4. A construction as defined in claim 3, wherein the means for actuating the feeding means includes a ratchet for operating the feeding means, a lever pivoted on the frame and operated in that movement of the slide tending to move the movable die to inoperative position, and a pawl operating the ratchet in material-feeding direction at each operative movement of the lever.

5. A construction as defined in claim 3, Wherein the means for actuating the feeding means includes a ratchet for operating the feeding means, a lever pivoted on the frame and operated in that movement of the slide tending to move the movable die to inoperative position, a pawl operating the ratchet in material-feeding direction at each operative movement of the lever, and means for adjustably controlling the operative movement of the lever to correspondingly control the feeding of the material.

WILLIAM HERBERT SMITH. 

